The power of a rotary steering tool is provided by a surface drilling rig. However, in the drilling operation in a deep well or extra-deep well, the rotary steering tool can't obtain high rotation speed and torque from the surface drilling rig owing to a fact that the friction resistance on the downhole casing and drilling string is increased. In such a case, a screw drilling tool may be used to provide power to the downhole steering tool. A high-performance screw drilling tool may be disposed between the rotary steering tool and an integrated MWD/LWD to provide high rotation speed and high torque to the rotary steering tool, so as to improve the drilling efficiency. In that way, it is unnecessary for the surface drilling rig to provide an excessively high rotation speed. Thus, the wear and fatigue of the upper casing, drilling string, and drilling tool assembly above the screw drilling tool can be reduced significantly, so that the risk and cost can be reduced. Since the rotary steering system requires electric power supply and communication with the integrated MWD/LWD, power transmission and signal transfer through the screw must be realized, so as to supply the electric power generated by the upper generator to the rotary steering tool through the screw drilling tool, transfer the data measured by the rotary steering tool near the drill bit and the working state information of the rotary steering tool to the upper drilling tool assembly through the screw drilling tool, and transfer the steering commands from the upper downhole central control system to the steering tool through the screw drilling tool.
For the communication between the rotary steering tool and the integrated MWD/LWD, usually a wireless communication technique is used in the prior art. Specifically, receiving and transmitting antennae are installed on the integrated MWD/LWD and the rotary steering tool, and communication is provided with an electromagnetic wave technique. However, that approach hasn't solved the problem of electric power supply to the rotary steering tool.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies